Nickel bis(dithiolene) complexes for electrocatalytic hydrogen evolution: A computational study

Abstract The substituent effect of dithiolene ligand on electrocatalytic activity of Ni bis(dithiolene) towards hydrogen evolution reaction (HER) are thoroughly explored with computational methods. A series of differently substituted dithiolene ligands are compared and evaluated. These computational results indicate that adding electron-withdrawing groups on the ligand or enlarging the conjugate Π system of the ligand can greatly reduce the reduction potentials, while tuning the electronic structure of the non- innocentframework can optimize the geometry of dihydrogen species to achieve lower energy barrier for H 2 elimination. This study may benefit the deep understanding of the electrocatalyzed HER mechanism and give inspirations on the design of efficient nickel bis(dithiolene) electrocatalystswith low overpotentialand improved kinetics.